1. Field of the Invention
The present invention relates to an automobile interior component which suppresses the generation of sharp-edged part fragments and the like when an automobile is impacted in a collision and the like in order to improve safety for vehicle occupants and to a manufacturing method for the component.
2. Description of the Related Art
In automobile side panels such as a door interior panel, a door trim is generally upholstered as an interior component.
Referring to FIGS. 13 and 14, a door trim 1 is composed of a laminated board including a resin core member 2 formed in a desired curved shape, having a shape-holding property, and a surface skin member 3 integrally attached to a part of the surface of the core member 2, having cushioning and decorative properties. The door trim is fixed to the inside of a door panel 4 which is a side panel of a body through such as a grip (not shown). In this door trim 1, an impact area (a) is provided where a shoulder, chest, waist, etc. of a vehicle occupant are likely to be impacted when a physical shock is applied from the side of the automobile, while an interference area (b) is set up for an area where the trim interferes with adjacent parts such as an instrumental pad.
For a forming method of the door trim 1, a mold press forming method is generally used in view of freedom in a product form and forming efficiency as shown in FIG. 15. This method is carried out by a mold press assembly essentially consist of a lower die 5 for mold press forming, an upper die 6 for mold press forming, and an injection molding device 7 connected to the lower die 5. When the lower die 5 and the upper die 6 are separated, the surface skin member 3 is set on the die surface of the upper die 6. Then, when the upper die 6 is lowered to the position that a predetermined clearance is defined between the upper and lower dies, resin material for a core member 2 is supplied by the injection molding device 7 through a gate 5a disposed at the lower die 5. After that, the upper die 6 is lowered to a bottom dead point, the core member 2 is formed into a required shape so that the core member 2 and the surface skin member 3 are integrally attached simultaneously. As for a conventional material for the core member of a door trim, a polypropylene resin with filler such as talc is used. In the impact area (a), the interference area (b), and rest portion, the same material has been used. Therefore, when a large physical shock is applied from the side of the automobile in a side collision, for example, there has been indications of the possibility of damage to the core member 2 and the generation of sharp-edged fragments of the component, in the impact area (a) where a shoulder, chest, and waist of a vehicle occupant are prone to be damaged and in the interference area (b) where the trim interferes with other parts such as an instrumental pad.
Accordingly, in order to prevent the generation of sharp-edged fragments, a special configuration for the surface skin member 3 is necessary, such as backing a sheet having a barrier property with the conventional surface skin member. This results in increasing the cost of the surface skin member, which is a problem in the overall automobile cost.
Since the conventional core member does not have a shock-absorbing property in the impact area (a) and the interference area (b), it has been urgently necessary to provide a shock-absorbing property in the specially required portions of the door trim 1.
In view of the above-mentioned problems, it is an object of the present invention to provide an improved interior component for a side panel of an automobile and its manufacturing method. More specifically, it is an object of the invention to provide an interior component and the method for manufacturing thereof, in which an increased shock-absorbing property and a reliable preventive property against the generation of sharp-edged fragments of the component are provided in the impact area where a shoulder, chest, and waist of a vehicle occupant are prone to be damaged and in the interference area where the trim interferes with other parts such as an instrumental pad. Since this component is capable of effectively absorbing the shock on the vehicle occupants and reliably preventing generation of sharp-edged fragments as well, generally used surface skin material can be used resulting in reduced cost.
In order to achieve the aforementioned object, according to a first aspect of the present invention, there is provided an interior component for an automobile, comprising: a core member formed into a desired shape, having a shape-holding property; and a surface skin member integrally attached on the part of the surface of the core member, wherein in the core member, high-impact resistant core members with a rubber-base ingredient are disposed at least either an impact area where a shock load is concentrated in a collision or an interference area to interfere with other parts.
It is preferable that as material for the core member for general portions, a thermoplastic resin with filler such as a polypropylene resin with talc be generally used, and as resin material for the high-impact-resistant core member, a polypropylene resin with talc and a rubber-base ingredient, for example, be used wherein the material is prepared so that the talc content is 10 to 15 parts by weight and the rubber base ingredient content is 20 to 30 parts by weight to the total weight.
In accordance with second aspect of the present invention, there is provided an interior component for an automobile, comprising: an injection molded object of a synthetic resin which is upholstered in a side-panel of a vehicle, wherein in the interior component, high-impact resistant core members with a rubber-base ingredient are disposed at least either an impact area where a shock load is concentrated at a collision or an interference area to interfere with other parts.
In this case, in the automobile interior component comprising a molded resin object, the high-impact resistant core members are also placed in the impact area and/or the interference area to interfere with other parts.
In accordance with third aspect of the present invention, there is provided a manufacturing method of the interior component, comprising the steps of: supplying resin material for a core member for general portions through gates disposed in the lower die of a mold press assembly for mold press forming, to predetermined portions of a lower die for mold press forming, and simultaneously dividing and supplying high-impact resistant resin material through a gate, to at least either a portion of the lower die corresponding to an impact area of the interior component or a portion of the lower die corresponding to an interference area of the interior component to interfere with other parts; and
an upper die for mold press forming, where a surface skin member is set in advance, is brought into engagement with and urged to the lower die for mold press forming, whereby high-impact resistant core members are formed in portions of the interior component corresponding to the impact area and the interference area to interfere with other parts.
While one of two injection molding devices connected to the lower die for mold press forming supplies resin material for the core member for general portions to the predetermined portions of the lower die surface through the gates, the other injection molding device supplies the high-impact-resistant resin material to the impact area and/or to the interference area to interfere with other parts through the gate.
As resin material for general portions of the core member, a general purpose thermoplastic resin with filler such as a polypropylene resin with talc is generally used, and as high-impact-resistant resin material, a resin with a rubber base ingredient is used.
As for the timing for supplying from two injection molding devices, they may be simultaneous or sequential. Timing may be appropriately adjusted, in consideration of an occupied space of each area and MI values of resins, etc.
In accordance with another aspect of the present invention, there is provided a manufacturing method wherein concave channels are formed on the die surface of the lower die for mold press forming along the boundary portions between the resin material for the core member for general portions and the high-impact resistant resin material for the high-impact-resistant core member.
In accordance with fourth aspect of the present invention, there is further provided a manufacturing method of an interior part for an automobile, comprising the steps of: setting a surface skin member to an upper die for mold press forming, and setting high-impact-resistant core members preformed into desired shape to portions of a lower die for mold press forming corresponding to an impact area and an interference area to interfere with other parts simultaneously; and supplying resin material for a core member to a die surface of the lower die for mold press forming through gates disposed in the lower die for mold press forming, whereby the high-impact-resistant core members are formed in the impact area and the interference area to interfere with other parts of the interior part by engaging and urging of the upper and lower dies for mold press forming.
In accordance with fifth aspect of the present invention, there is finally provided a manufacturing method of an automobile interior component composed of an injection molded object of a synthetic resin which is upholstered in a side-panel of a vehicle, comprising the steps of: injection-filling resin material for a core member for general portions into cavities defined between upper and lower dies for mold press forming; and then injection-filling high-impact resistant resin material for high-impact-resistant core members in portions corresponding to an impact area and an interference area to interfere with other parts, whereby the high-impact-resistant core members are embedded into the core member for general portions.
As is apparent from the above-mentioned configurations, since a high-impact-resistant core member is used in the impact area where a shock load is concentrated and in the interference area where the trim interferes with other parts, the shock load can be effectively absorbed and sharp-edged fragments from rupture of the core member can be suppressed when a side shock load is applied.